That's where I learned that contrary to popular belief, neither is incorrect, and they both mean "to fit in," "make sense of," or "be in harmony with."

JIBE is the older of the two, making its appearance in print around 1813.

JIVE, the much younger word sibling (showing up in 1943 with this meaning), is just as legitimate, if newer.

(Those who favor JIBE will be happy to know that some dictionaries don't include this definition under JIVE.)

My guess is that JIBE shifted to JIVE as result of what people thought they were hearing.

The B sound in JIBE is easily softened and almost non-existent when you say "it doesn't jibe" quickly. If JIBE doesn't have another word after it, the B almost disappears entirely.

Then with the creation of swing music, people would JIVE, and that word was far more common that JIBE (which originally was a SAILING term back in the 1600s). Without getting all technical, both sounds are made at the front of the mouth; it's easy to see how one could morph into the other.

That's how, in my word nerd but non-professional opinion, I think JIVE took on the meaning of JIBE.

And today we use both. (You'll find JIBE/JIVE on page 68 of my grammar book, but not in so much detail.)